Carbon-feeding mechanism.



W. G. PREDDEY. CARBON FEEDlNG MECHANISM. APPLICATION FlLED MAY 29. 1916.

Patented Sept. 11, 1917.

WITNESSES E N R O T T A B UNITED STATES PATENT armor.

WALTER G. PREDDEY, OF SAN FRANCISCO, CALIFORNIA.

CARBON-FEEDING mnenanrsm.

Specification of Letters Patent.

Patented'sept. 11, 1917.-

Application filed May 29, 1916. Serial No. 100,684.

each other, to compensate for the combustion which takes place at the are.

This invention has for its object primarily to rovide a carbon feeding mechanism he above description which will prevent an abnormally highvoltage across the are when the same is burning. A further object is to increase the steadiness of the light, due to the uniformity of the feed movement.

A still further object is'to provide a means whereby the voltage across the arc can be adjusted without shutting down the motor which is running when the arc is in operation.

With these ends in view my invention consists in the details of construction and combination of elements hereinafter set forth, and then specifically designated by the claims. Its construction and operation will be described in detail, referring by numerals and letters to the accompanying drawings forming a part of this specifiers tion, and in WhlCll similar numerals and letters of reference designate corresponding parts in all figures.

In the accompanying drawings :Figure 1, is a schematic new of an ordinary arclamp circuit equipped with my improved carbon-feeding mechanism. Fig. 2, is an enlarged detail side elevation of the periodic circuit closer 1 and centrifugal-contactor comprising parts 2, 3 and 4 as shown in Fig. 1. Fig. 3, is an enlarged side view of electro-magnetv 12 and feeding mechanism 13 ,50 and 1 1 as shown in Fig. 1.

Referring to the drawings, A and A are line wires connecting to service wires through a compensator, transformer, rectifier or resistance, and supply current to the carbons. Motor circuit wires B and B are shown connecting motor6 in multiple with- The carbon feed con-- line wires A and A trolling circuit C, C and C is a derived circuit in multiple with are circuit A and A and motor circuit B and B A periodic circuit closer 1 is shownfixedly attached to the'shaft 8-of motor 6. A brush 5 conducts current from line A through wire C to periodic circuit closer 1. A segment9 forming a part of commutator 1 consists of a piece of insulating material which breaks the circuit as it passes brush 5. The parts 2, 3 and 1 comprise a centrifugal-contactor; 2shows a metallic hub, 4 a weight, connected'together by a spring The standard .10 supports an adjustable screw 11 forming a stationary contact. An electro-magnet 12 is connected to lines A and A through circuit C, C and C and operates feed-rod-15 by means of pawl 13 and ratchet-wheel, 1 1.- An insulating base 16 secures motor 6, brush 5 and stationary contact 10 in place.

In carrying out my invention I preferably employ a motor of the commutator type shunt wound, the speed of which proves to be more sensitive to variation in voltage across the terminals of same. On the shaft 8 of the motor is fixedly attached an ordinary periodic circuit closer which makes and breaks the shunt circuit C, C and C producing an intermittent current as it passes conducting brush 5. ()u the same shaft a contrifugal-contactor comprising parts 2, 3 and t is fixedly attached and con nects electrically to criodic circuit closer 1 through shaft 8. n adjusting screw 11 limits the distance between the points of contact when the motor is in operation, which determines the voltage across the arc. The electro-magnet herein shown in preferably of the ordinary type consisting of an iron core wound with wire which actuates the feed mechanism of lamp by means of the prising the armature of said electro-magnet.

awl and ratchet-wheel, the pawl com-- This arrangement is particularly adapted to hand-feed arc-lamps, such as those now commonly used for moving picture machines, and has the advantage of remote control. The electro-magnet 12 and the feeding mechanism 13 and 1% is fixedly attached to the feed-rod of the arc-lamp, while the motor, periodic circuit closer, centrifugal-contactor and adjusting contact screw can be located at any desired distance from the are or placed in any position, which insures its protection from extreme heat and carbon dust which is a recognized menace to operating mechanism forming part of an arc-lamp.

The operation of this device will then be as follows: The carbons being connected to a proper source of supply by line wires A A through a rectifier, the line switch is then closed and the carbons brought in contact and separated by feed-rod 15 to establish the arc. On closing the line switch the motor immediately starts running, the speed of which will be in proportion to the voltage across the terminals of same, which in turn depends on the distance between the carbon points of the arc. If the carbon points are far apart the voltage of the feed circuit A and A raises which speeds up the motor, which in turn closes the circuit C, C and C through the centrifugal-contactor and comletes the circuit through electro-magnet 12 en the motor is up to the speed that closes the centrifugal-contactor and the circuit is complete, the periodic circuit closer produces an intermittent current through the relay 12 which energizes the iron core of same and attracts the pawl 13, which in turn operates the feed-rod 15 by rotating ratchet-wheel 14, thus feeding the carbons until they are close 'enou h for the voltage to drop across the terminals of the motor and lower the speed of same'which simultaneously opens the centrifugal-contactor and electro-magnet 12 ceases to operate. When the consumption of the carbons is sufficient to raise the resistance of the are which increases the voltage across same, the operation is repeated, thus, producing a constant voltage across the are, which in turn increases the steadiness of the light from same. Any given voltage may be obtained across the are by adjusting the dis tance between contact points of centrifugalcontactor, by means of adjusting screw 11.

While I have illustrated and described the preferred construction and arrangement of the various parts, it will be obvious from the foregoing description that the device is susceptible of considerable modification, without departing from the essential features or sacrificing any of the advantages thereof as come within the scope of the claims appended hereto.

Having thus fully described my invention,

what I claim as new and desire to secure by Letters Patent is 1. In a carbon feedin mechanism, the combination of an arc CII'CIlliJ and an arc lamp connected thereto, an electric motor operating from the arc circuit and the speed of same varying with the voltage of said are circuit, a periodic circuit closer and a centrifugal switch attached to the rotating member of said motor, and a circuit including a source of E. M. F. and said circuit closer and switch and means responsive to the intermittent closure of the circuit for feeding one of the electrodes toward the other.

2. In a carbon feedin mechanism, the combination of an arc circuit and an arc lamp connected thereto, an electric motor operating from the arc circuit and the speed of same varying with the voltage of said circuit, a periodic circuit closer and a -centrifugal switch attached to the rotating member of said motor, a circuit including a source of E. M. F. and said circuit closer and switch and means responsive to the intermittent closure of the circuit for feeding one of the electrodes toward the other, and said centrifugal switch having means for adjusting contacts of same.

3.'In a carbon feeding mechanism, the combination of an arc c rcuit and an arc lamp connected thereto, an electric motor operating from the arc circuit and the speed of same varying with the voltage of said circuit, a periodic circuit closer and a centrifugal switch attached to the rotating member of said motor, a circuit including a source of E. M. F. and said circuit closer and switch and means responsive to the intermittent closure of the circuit for feeding one of the electrodes toward the other, and one contact of said centrifugal switch being stationary.

1. In a carbon feedin mechanism, the combination of an arc circuit and an arc lamp connected thereto, an electric motor operating from the arc circuit and the speed of same varying with the voltage of said circuit, a periodic circuit closer and a centrifugal switch attached to the rotating member of said motor, a circuit including a source of E. M. F. and said circuit closer and switch and means responsive to the intermitweaved Q said electro-magnet operating a pawl and.

ratchet for actuating feeding gear.

in testimony whereof I have hereunto set my hand in presence of two subscribing witmesses.

WALTER G. PREDDEY.

Witnesses:

J. M. TRIPLE'IT, Mo. DAVIS. 

